1. Field of the Invention
The invention relates to an investigation device and an investigation method. More particularly, it relates to a device for picking of particles from a sample and analyzing them with a mass-spectrometer.
2. Background of the Invention
Japanese disclosure, JP 061 95155, discloses a region surface analyzing method and device. A surface atom of a specimen is stuck to the tip of a probe. A specimen holder is removed from a scanning tunneling microscope and placed outside the time of flight of an ion. When a switch is switched, output voltages of a straight polarity from a high voltage power source and a straight polarity from a pulse generator are adjusted to generate a pulse. The pulse generated is picked up by a logos key coil and a clock of a mass spectrometry system using a time of flight method is started. When the ion is separated, the clock is stopped by a signal sent from an ion detector and the time difference between the stop signal and the start signal, the time of flight, is recorded. An element is identified based on the time of flight.
In an article entitled, xe2x80x9cAtomic species identification in scanning tunneling microscopy by time of flight spectroscopyxe2x80x9d by Spence, Weierstall, and Lo, Journal of Vacuum Science Technology, B 14(3), May/June 1996, pp. 1587-1590, it is described how atoms at particular sites can be selected from an STM or AFM image for identification. Atoms from a sample are picked up with a tip, the sample is the being removed and a much larger voltage pulse is applied causing field evaporation of these atoms into a time of flight mass spectrometer.
The invention is directed to an investigation device comprising a time of flight mass spectrometer with an entrance opening, and an electrically conductive tip which is movable from a first position near a sample on a sample holder to in a second position near the entrance opening. The tip is located at a cantilever. In the case where a sample is located on the sample holder, a sample particle can be obtained when the tip is in the first position located next to the sample. The tip, having obtained the particle, is movable into the second position where the particle can be accelerated towards the entrance opening. The particle is then analyzable in the time of flight mass spectrometer.